Sound-box construction



Mar. 20, 1923, y 1,448,872.,

L. K. SCOTFORD.

SOUNDl BOX CONSTRUCTION. FILED JAN. 23, 1920.

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A fave/1W" Low@ 560270716X,

Patented ar. 2, i923.

'oFICE- LOUIS K. SCOTFORD, 0F C-ZCAGO, ILLINOIS.

SOUND-BOX CONSTRUCTION.

Applicant filed January as, i920. serial no. 353.513.

mounting the vibration transmitting bar and needleholder on a sound boxon knife-edge or pointed supports without the use of springs for holdingthe various elements in contact with the knife. edges or points.

1n orderl to truly reproduce recorded sound, it is necessary that themovements of the needle be transmitted to the vibration transmitting barwith minimum lostmotion. In view of the fact that the relative move*ment of the needle with respect to the sound box is slight, thecommunication between the needle holder, vibration transmitting arm andthe diaphragm must be so sensitive as to reproduce faithfully andclearly the recorded sound. 1 have found that the best form of mountingthe various elements going to transmit the recorded sound from theneedle to the diaphragm includes mounting the vibration transmitting armon points or knife edges, thereby reducing' friction to a minimum` l amaware of the fact that the mounting of the various parts on knife edgesis old, as this mounting has been practiced considerably in the past andis employed at the present time. Iowever, the present arrangementsemploy springs for maintaining the contact of the various parts againstthe knife edges, and` springs possess inherent faults which hinderperfect functioning of the parts to faith' fully reproduce therecordedsound. My invention provides a knife edge or pointed support for theneedle holder and vibration transmitting bar without using springs,Furthermore, it provides means for adjusting Within certain limits theengagement between the knife edges and the parts mounted thereon. n

One of the objects of my invention is to provide in a sound box knifeedge supports or the vibration transmitting bar and needle arm withoutusing springs or equivalent means. i

Another object is to provide a knife edge mounting for vibrationtransmitting arms and means for adjusting the engagement between theknife edges and the supported parts.

A further obj ect is to provide a knife edge support for sound boxconstruction which will be simple, easily adjusted and economical tomake.

A still further object is to improve sound box construction forsuccessful commercial use.

By referring to the drawings, the objects of my invention will beapparent.

In the drawings* Figure l is a front elevational view of a sound boxembodying my invention;

Figure 2 is a side elevation of thebox of Figurel;

Figure 3 is an enlarged fragmentary view partially in section showingthe preferred knife edge construction of my invention;

Figure 4f is ahorizontal sectional view on line 4-4 of Figure 3;

Figure is a sectionall view on line 5--5 of Figure 3; i

Figure 6 is a view similar to Figure 3 showing a modified form of myinvention;

Fig. 7 is an enlarged view of certain details of construction; and

Figure 8 is a section taken on` line 8-8 of Figure 6.

, My invention is shown in connection with a. sound box l() having theusual diaphragm ll at the center of which is secured the upper end ofthe vibration transmitting bar l2. Extending from the rear side of thesound box l0 is an elbow-shaped tone-arm connector 18, which is adaptedfor association with a tone arm, and arranged so that the free end isparallel to the diaphragm.

My invention also contemplates a needle holder separate from thevibration transmitting arm. 0n the rearside of the sound box, that is,on the same side with the'tone arm connector 13, is suitably mounted abracket la having a horizontally disposed opening 15 therethrough. Thelower portion of the vibration transmitting arm l2 is bent .backwardlyand terminates in an enlargement or head 16 in which is formed ahorizontally disposed wedge-shaped opening 17 and having a verticallyextending apof my invention has its upper end 19 shaped similarly to theenlarged end 16 of the vibrationr transmitting bar, and isv providedwith a'wedge-shaped opening and a vertically disposed aperturetherethrough similarly arranged to the corresponding partsV in theenlarged portion 16 of the vibration transmitting bar. For bodilylongitudinal movement in the opening 15 of the bracket 14 I mount twoknife edged members 20, 217 which are alike in every respect. Thesemembers have the portions indicated by the reference characters 20, 21of Acylindrical shape, terminating in rounded rear ends 22. The otherportions ofthe members are fla-tytened, formingwedges or knife edgemembers 23. yIn Figure 4 it will be noted that the members 23 lare cutout at 24 for a purpose to be hereinafter explained. These members aremounted as shown in the iigures of the drawing so that the knife edgeportions 23 extend beyond each end of the bracket 14 and engage theV-shaped openings the head 16 of the vibration transmitting bar 12 andthe needle holder 19. Throughthe vertically disposed apertures in theheads 16 and 19 are passed pins 25, which pins. have reduced heads 26,and between the heads and the body portions of the pins are formedrecesses 27. For coopj erating with the pins and engaging vthe recesses27 I provide top and bottom links or straps 28 which have head portions29 providing a cut-out part in size just suflicient to pass over thereduced head 26 of the pins ,25 and having a knife edge 30 for engagingthe recesses 27 of the pins In assembling the device the knife edgemembers 2O and 21 .are inserted in back to back relation, as shown inFigures 3 and 4 of the drawing, and then the heads 16 of the vibrationtransmitting bar 12 and of the needle holderl 19 are positioned thereon,the pin previously having` been inserted inthe apertures thru.

these heads, whereupon the engaging links '28 are applied as shown inFigure For tightening the device to properly adjust the members 16 and19 to move on the knife edges 23, I employ a set screw 31 carried in thesideiof the bracket 14. This screw is provided with a point engaging therounded ends 22 of the members 2O and 21 so that inward or outwardmovement of the screw will move the members 20 and 21`to properly ten-`wise movement of the needle holder and vi bration transmitting bar.

I so position the parts that the axis of the needle', which is retainedin therecesses 32 0f the needle ,holder by a set screw 33, is inalignment with the' axis through the portion 13 of the tone armconnector'. Iiith this construction it is possible to employ my soundbox in connection with both zigzag and hill-and-dale records. The soundbox may be mounted on the tone arm in the position shown in Figure2 forplaying zig- Zag7 records. By reason of the fact that the needle is inaxial alignment with the tone arm connector 13 the box may be turnedthrough an angle of degrees into the position of Figure 1,'so thathill-and-dale records may be reproduce l. This feature is of greatadvantage, as will be apparent to those skilled in the art. It may' herebeobservedthat with my invention it is possible to reproducechill-and-dale7 and Zig-Zag7 records with a single sound box, thequality ofv the reproduction in each case being the same. This isbrought about'by the novel, method of mounting theneedle holder withrespect to the tone arm connector. j Furthermore,-it may be observedthat I have provided a knife edge mounting for a vibration transmittingbar and needle holder eliminating entirely the springs which have provedto be of uncertainl quantity and which in order to admit the parts tofunction properly must always be uniform, which characteristic ishard toattain when quantity production of springs, sound boxes'and 'parts issought.

In the modification shown in Figure 6. the bracket has been extended tooverli'e the needle holder and adjacent end of the vibrationtransmitting bar, both of'which have portionsextending into an openingin the bracket. In Figure 6 the vibration transmitting bar 12 has a headportion having` formed on one side of a vertical axis therethrough twoV-shail'ied recesses 35. one above the othery andon the opposite sidesingleA Vfshaped recess 36. the bases of the recesses lying` in the samevertical pla-ne. Similarly. the `needle holder is provided with a head37 having recesses arranged similarly to those of the head'34." butpositioned in the opposite direction. Atthe vibration transmitting barside of the bracket is securely fixed a knife edge 36 for. engaging therecess 36 of the head34.` For soparating the needle holder and vibration.trans mitting bar I provide a pair of pointed spreaders 319, the angleof the points ot' which is sharperY than the angle ofthe receases As ameans ofsecuring adjustnient of the knife edge construction of 'Fig-4ure 6 the knife edge 40 which `supports the needle holder is mounted tohave bodily` movement of the bracket, and this movement maaar/a isgoverned by a set screw All suitably positioned to engage the rear otthe .knife edge `l0. ln this construction it will be noted that l havesecured the same relation be t veen the needle holder and vibrationtransmitting bar as l have in the lirst torni, and that the uniformityot movement betvveen the needle holder and vibration transmitting bar inboth cases is the same. l/Vhen the arrangement ot Figure 3 is used inconnes tion With the sound box the various: parts are so proportionedthat the axis ot the needle carried in the needle holder will lie in theaxis of the tone arm connector i3 in same manner as described inconnection With the arrangen'ient or" the lirst form` lWhile l havedescribed more or less pre cisely the details ot construction oi myinvention, l do not Wish to be understood as limiting myself thereto, asl contemplate changes in term and the proportion ci parts andsubstitution ot' equivalents as circumstances may suggest or renderexpedient,

Without departing from the spirit of my inv vention.

l claim:

l. ln a sound box construction. a needle holder and a vibrationtransmitting bar each mounted thereon and located in spaced lateralrelation, and means connecting said needle holder and said vibrationtransmitting bar for transinitting movement irom one to the other.

2. A sound box construction having;` a vibration transmitting bar and aneedle holder, said members being maintained in spaced relation, meanssupporting said members on said sound box, said means including kniteedge members, and inelastic means associated with said needle holder andsaid vibration. transn'iitting bar ttor maintaining the same inengagement 'with said knife edge members.

3. A sound box construction h ving a vibration transmitting bar and aneedle holder, said members being maintained in spaced relation, meanssupporting said inembers on said sound box, said means including knifeedge members, inelastic means associated with said needle holder 4andsaid vibration transmitting bar 'for maintainng the same in engagementwith said knite edge members, and means tor adjusting the engagement ofthe parts on the knife edge members Within certain linfiits.

4t. ln a device ol' the class described, including in combination avibration transmitting bar and a needle holder in lateral spacedrelation thereto, a bracket depending from the sound box, said bracketsupporting knife edge members engaging said vibration transmitting barand needle holder, means connecting said vibration transmitting bar andneedle holder for maintaining the same in operative relation on saidknife edge members, and means tor adjusting the operative relation otsaid needle holder and Tibration transmitting bar.

5. A sound box having a vibration transmitting bar and a needle holder,means for transmitting movement trom the needle holder to the vibrationtransmitting bai', said means including a pair ot' parallel menibersextending between the needle holder and vibration transmitting bar, andmeans engaging said holder and bar tor maintaining same in associationwith said parallel members.

6. n, sound box ot the class described, having a needle holder and avibration transmitting bar,` a bracket depending from the loiver portionof the sound box and having an opening therein, said vibrationtransmitting bar being supported at one end of said bracket and theneedle holder at the other end thereof, and means transmitting movementtrom the needle holder to the vibration transmitting bar.

7. A sound box construction including separated vibration transmittingbar and needle holder, the same being mounted in siaced relation andincluded in a vertical p ane normal to the plane ot the diaphragm, knifeedge members adapted to support said vibration transmitting bar andneedle holder to permit rocking thereof, and means extending betweensaid vibration transmitting bar and needle holder tor kmaintaining thelatter in engagement; with said knife edge members.

8. A. sound box construction including separated vibration transmittingbar and needle holder, the same being mounted in spaced'relation andincluded in a vertical plane. normal to the plane ot diaphragm, knifeedge members adapted to support Said vibration transmitting bar andneedle holder to permit rocking thereof, means extending between saidvibration transmitting bar and needle holder tor maintaining the latterin engagement with said knife edge members, and means tor adjusting theengagement of the vibration transmitting bar and needle holder withrespect to said knife edge members.

9. In a sound box construction, a needle holder and a vibrationtransmitting' bar separately pivoted on said box in spaced lateralrelation.a and an articulated connection bet-Ween said needle holder andvibration transmitting bar for constraining simi* lar movement in thetivo members.

l0. ln a sound box construction, a needle holder and a vibrationtransmitting bar mounted on said box in such manner as to bring theouter end ot the vibration trans niitting bar and the inner end of theneedle holder in substantially the same horizontal plane and in spacedlateral relation, and means connecting said needle holder and v1-liraton transmitting bar for rzmsinitting plaine and in spaced lateralrelation, and an movementifrom one to the other. aricnlated Connectionbetween said needle l0 il. ln a sound box cons'ruction, a needle holdersind vibration transmitting bar for holder and a vibration transmittingbar transrniting moi/ement from one to the mounted on said boi; in suchmanner as to other.

bring che ouer end of the Vibration trains- Signed at Chicago, lllinois,this Meth day initting har and the inner end of the needle of January,1920. holder in substantially the graine horizontal LOUIS K. SCOTFURD.

